The BGW model for QoS aware scheduling of real-time embedded systems
The BGW model for QoS aware scheduling of real-time embedded systems
复制标题
实时嵌入式系统QoS感知调度的BGW模型
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
Audrey Queudet
中科院分区：
文献类型：
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作者：
Mohamed Ould Sass;M. Chetto;Audrey Queudet
实时计算系统中的任务通常是周期性的。调用周期性任务生成的每个实例通常都有一个最后期限约束，根据该约束，它必须在所有情况下完成其执行。然而，软件中可能存在故障，电源可能耗尽，处理器可能瞬时过载等。这些紧急情况中的任何一个都涉及不再可能满足应用程序中所有实例的最后期限的情况。
在本文中，我们讨论了应用程序任务集的通用模型，该模型允许操作系统根据静态附加到每个任务的特定参数以及其经典的计时参数来正确管理上述紧急情况。该模型的灵感来自于著名的 Deadline Mechanism 和 Skip-Over 模型。我们引入了 BGW 模型，其中任何周期性任务的每个实例都可以获得黑色、灰色和白色三种颜色之一。颜色指定实例必须强制执行主要版本，实例必须执行主要版本和备用版本中的至少一个版本，否则实例可能被丢弃。我们简要讨论这个新模型的实施问题。
Tasks in a real-time computing system are commonly periodic. Each instance generated by the invocation of a periodic task has normally a deadline constraint by which it must complete its execution in all circumstances. However, faults may be present in software, the electrical power supply may be depleted, the processor may be overloaded transiently etc. Any of these emergencies involves a situation where it is no longer possible to meet the deadlines of all the instances in the application.
In this paper, we discuss a general model for the application task set that permits the operating system to correctly manage the above emergency situations in accordance with specific parameters statically attached to every task in addition to its classical timing parameters. The model is inspired by the well-known Deadline Mechanism and Skip-Over model. We introduce the BGW model where each instance of any periodic task can get one of the three colours Black, Grey and White. A colour specifies that the instance has to imperatively execute the primary version, the instance has to execute at least one version among primary and alternate or the instance may be discarded. We briefly discuss implementation issues for this new model.